Storage type water heating method and storage type water heater

ABSTRACT

According to the present invention, hot water having a desired temperature can be generated in a short time by forcibly mixing low temperature water with high temperature water, the capacity of a hot water storing tank may be a about half of that of a conventional hot water storing tank, and a water heater can be downsized and made lightweight, and the manufacturing cost and installation cost thereof can be saved. A hot water storing tank  1  has a water supply port on a base plate  2 B side, and a water supply port  4  on a top plate  2 C side. A suction port  14  is formed in the hot water storing tank  1  so as to be positioned at the same height as or lower than the water supply port  3,  and a jet port  15  is formed in the hot water storing tank  1  so as to be positioned in the vicinity of the water supply port  3.  A hot water generating and jetting device  11  having a circulation pump  13  connected to the suction port  14  and the jet port  15  includes a casing  12,  a temperature sensor  16,  an electric heat type water heater  17  and a control panel  18.

TECHNICAL FIELD

The present invention relates to a storage type water heatingtechnology, more particularly, it relates to a storage type waterheating method and storage type water heater in which the supply amountof hot water is secured, while a hot water storing tank is downsized,and the heat source cost can be saved.

BACKGROUND ART

As shown in FIG. 4, a conventional storage type water heater includes: ahot water storing tank 51; a water supply port 52 provided in a bodypart 51B so as to be positioned near a bottom 51A; a water supply port53 provided in a top plate 51C; and, a rod-shaped sheath heater 54inserted at the bottom side of the hot water storing tank 51.Additionally, when water in the hot water storing tank is heated by thesheath heater 54, generated hot water slowly rises by naturalconvection, and thus a high temperature water region HW having atemperature of, for example, about 98° C., and a low temperature waterregion LW are generated at the upper part and lower part in the hotwater storing tank 51, respectively. Further, it is found that distincttemperature layers W₁, W₂, . . . Wn are formed via temperature layerinterfaces S1, S2, . . . Sn respectively, each temperature differencebetween the temperature layers being about 10° C.

The temperature layers formed in the hot water storing tank indicate thetemperature of the hot water in the hot water storing tank isconsistently uneven. However, this problem has not yet been clearlysolved.

DISCLOSURE OF THE INVENTION

Since temperature layers W₁, W₂, . . . Wn are thus formed in hot waterin a hot water storing tank 51, each temperature difference between thetemperature layers being about 10° C., the hot water having atemperature of, for example, 85° C. or more, which is usable as hotwater, is about half of the whole capacity of the hot water storing tank51. Accordingly, the following problems remain: first, a large hot waterstoring tank having a capacity twice as large as that of a conventionaltank must be used in order to secure the supply amount of hot water perunit time; second, price and installation construction cost of the hotwater storing tank are high; third, a wide space is required forinstallation; and, fourth, since the capacity of the hot water storingtank is large, it takes time to obtain hot water having a desiredtemperature, and cost of heat source such as power consumption is high.

In the inventor's consideration regarding the temperature layers ingenerating hot water with conventional technology, and in view of theabove problems, the present invention was made through the inventor'sdiligent research. It is an object of the present invention to provide astorage type water heating method and storage type water heater,wherein: the temperature layers formed by heating low temperature waterare forcibly mixed by jetting high temperature water, temperature layerinterfaces are destroyed, and thus the hot water having the desiredtemperature can be generated in a short time, hot water generated so asto wholly have an approximately evenly set temperature can be stored inthe hot water storing tank, and the cost of the heat source can besaved; and, since the capacity of the hot water storing tank may beabout half of that of a conventional tank, the tank can be downsized andmade lightweight, and thus manufacturing cost and installation cost canbe saved, and a space for installation can be cut in half.

In order to achieve the above object, in the present invention accordingto claim 1, a hot water generating and jetting device is externallyattached to a hot water storing tank having a water supply port and ahot water supply port, sucking water, generating hot water by heating,and jetting are repeated between the hot water generating and jettingdevice and the hot water storing tank, the temperature layers generatedby the hot water in the hot water storing tank are forcibly mixed sothat the temperature layer interfaces are destroyed, and approximatelyeven high temperature water is generated in the hot water storing tank,whereby the hot water storing tank can be downsized.

Additionally, in the present invention, water in the hot water storingtank supplied from the water supply port is heated by the heat sourcewhile being circulated by a circulation pump between a suction port anda jet port that are provided at the bottom side of the hot water storingtank, the heated water is jetted from the jet port and forcibly mixedwith the water in the hot water storing tank so that hot water having anapproximately even temperature is generated, and the generated hot wateris further heated to a desired temperature by the heat source whilebeing circulated by the circulation pump, and is supplied outward fromthe water supply port provided at the upper side of the hot waterstoring tank.

Further, the present invention includes: the hot water storing tankhaving the water supply port at the bottom side of the tank body, andthe water supply port at the upper side; and, a hot water generating andjetting device connected to the hot water storing tank. The hot watergenerating and jetting device has the circulation pump communicatingwith the suction port formed in the hot water storing tank so as to bepositioned at the same height as or lower than the water supply port,and with the jet port formed in the hot water storing tank separatelyfrom the suction port, heats the water sucked from the suction port bythe heat source, generates the hot water having an approximately eventemperature in a manner that the heated water is jetted from the jetport to be forcibly mixed with the water in the hot water storing tank,and further circulates and heats the generated hot water to a desiredtemperature while detecting the temperature of the generated hot waterby a temperature sensor.

Furthermore, the hot water generating and jetting device includes: thecirculation pump for circulating water by sucking and jetting betweenthe device and the hot water storing tank; the heat source for heatingthe water sucked by the circulation pump; the temperature sensor fordetecting the temperature of the water sucked from the hot water storingtank; and, a control panel for stopping operation of the heat source inaccordance with a signal transmitted from the temperature sensor, thesignal indicating the sensor has detected the temperature of the waterin the hot water storing tank has reached the desired temperature.

Additionally, the jet port may be formed at the bottom of the hot waterstoring tank.

The above and other objectives and features of the present inventionwill be clearly understood in consideration of the following descriptionwith reference to the accompanying drawings showing best modes forcarrying out the present invention as an example.

EFFECT OF THE INVENTION

As described above, the following effects are obtained by the presentinvention.

(1) In a conventional storage type water heater, temperature layersprevent hot water having an even temperature from being generated.However, according to the present invention, since high temperaturewater is jetted into a hot water storing tank and forcibly mixed withlow temperature water so that the temperature layers are prevented frombeing generated and temperature layer interfaces are destroyed, desiredhot water having an even temperature can be generated in a short time,and heating time is shortened so that the cost of a heat source can besaved.

(2) The high temperature water is jetted into the hot water storing tankand forcibly mixed with the low temperature water so that hightemperature water can be generated which has an approximately eventemperature throughout the whole of the hot water storing tank.Therefore, the capacity of the hot water storing tank may be about halfof that of a conventional hot water storing tank even if bothcapabilities of supplying hot water are the same, a water heater of thepresent invention can be downsized and made lightweight, and thus themanufacturing cost and installation cost of the heater can be reduced,and a space for installation of the heater can be reduced byapproximately half.

(3) A hot water generating and jetting device includes: a circulationpump for circulating water by sucking and jetting between the device andthe hot water storing tank; a heat source for heating the sucked water;a temperature sensor for detecting the temperature of the sucked water;and, a control panel for stopping operation of the heat source inaccordance with a signal transmitted from the temperature sensor, thesignal indicating the sensor has detected the temperature of the waterin the hot water storing tank has reached the desired temperature. Sincethe constitution of the device is relatively simple, the water heater issecurely operated, does not break down, and the manufacturing costthereof is saved.

(4) Since a jet port of the high temperature water is formed at thebottom of the hot water storing tank, jet pressure of the hightemperature water does not prevent water supplied from a lateral watersupply port from flowing into the tank. Additionally, since the hotwater is forcibly mixed with the high temperature water so that notemperature layer interface is formed, desired high temperature watercan be speedily generated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 2 show a First Embodiment, FIG. 1 is a perspective viewof a storage type water heater, and FIG. 2 is a figure showing an innerstructure of the storage type water heater. FIG. 3 is a view showing aninner structure of a storage type water heater according to a SecondEmbodiment. FIG. 4 is a diagram showing a hot water generation state ofa conventional storage type water heater.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below withreference to the accompanying drawings.

In the figures, the reference numeral 1 denotes a hot water storing tankmade of stainless steel or high strength synthetic resin formed so as tobe vertically long. The hot water storing tank 1 includes: a tank body 2constituted by a cylindrical body part 2A, a bottom plate 2B for sealingthe lower end of the body part 2A, and a top plate 2C for sealing theupper end of the body part 2A; a water supply port 3 formed on the lowerend side of the body part 2A of the tank body 2 and near the bottomplate 2B; and, a water supply port 4 formed at the approximate center ofthe top plate 2C. Additionally, a water supply pipe 5 such as a waterpipe is connected to the water supply port, and a hot water supply pipe6 for supplying hot water to a water faucet (not shown) is connected tothe water supply port 4.

The reference numeral 11 denotes a hot water generating and jettingdevice connected to the hot water storing tank 1 via a pipe. Thereference numeral 12 denotes a box-shaped casing constituting the hotwater generating and jetting device 11, and is attached to an outersurface of the body part 2A of the hot water storing tank 1 by propermeans such as screwing. Moreover, the casing 12 may be attached to awall, etc., in the vicinity of the hot water storing tank 1.

The reference numeral 13 denotes a circulation pump provided in thecasing 12. A suction pipe 13A of the circulation pump 13 is connected toa suction port 14, and a jet pipe 13B of the circulation pump 13 isconnected to a jet port 15. Here, the suction port 14 is formed in thebody part 2A on the bottom plate 2B side of the hot water storing tank 1so as to be approximately opposite to the water supply port 3.Additionally, the jet port 15 is formed at a position not opposite tothe suction port 14 and separately upward from the suction port byseveral tens of centimeters, and the circulation pump 13 repeats suckingand jetting water and hot water in the hot water storing tank 1 via thesuction port 14 and the jet port 15 to circulate the water and hotwater.

The reference numeral 16 denotes a temperature sensor provided in thesuction pipe 13A. The temperature sensor 16 detects the temperature ofthe water (hot water) sucked from the lower side of the hot waterstoring tank 1 through the suction pipe 13A via the suction port 14 totransmit a detection signal to the following control panel 18.

The reference numeral 17 denotes an electric heat type water heaterwhich is positioned on the jet side relative to the circulation pump 13and is connected to the pump via a communicating pipe 13C. In theelectric heat type water heater 17, an electric heater (not shown) isprovided in a can body 17A, and a power source switch, which isconnected to the following control panel 18 via signal wires (notshown), is provided on the electric heater.

Additionally, the reference numeral 18 denotes the control panelprovided in the casing 14. The control panel 18 has the functions of:setting the temperature of hot water to be supplied to an arbitrarytemperature, for example, 85° C. or 90° C.; deciding a differencebetween the current temperature and the set temperature based on atemperature detection signal transmitted from the temperature sensor 16;and, transmitting a signal for energizing the electric heater to thepower source switch based on the decided difference in temperature, ortransmitting a signal for stopping energizing of the electric heater tothe power source switch in the case where it is decided the differencein temperature is zero.

In the thus constituted storage type water heater of the embodiment, thewater supplied to the hot water storing tank 1 through the water supplypipe 5 is sucked by the circulation pump 13, heated into hot water whileflowing in the electric heat type water heater 17, and jetted into thehot water storing tank 1 from the jet port 15. In this case, since thesuction port 14 is formed opposite to the water supply port 3, lowtemperature water supplied to the hot water storing tank 1 from thewater supply port 3 is speedily sucked by the circulation pump 13, andthus the hot water in the hot water storing tank 1 is, as much aspossible, prevented from being cooled by the low temperature water.

On the other hand, the jet port 15 is provided at a position notopposite to the water supply port 3 and appropriately separated from thesuction port 14 so that supplying water from the water supply port 3 isnot obstructed by water pressure of the hot water jetted from the jetport 15. Additionally, high temperature water is jetted to the lowtemperature water in the hot water storing tank 1 so that thetemperature layers formed by heating the low temperature water areforcibly mixed and the temperature layer interfaces are destroyed, andthus the low temperature water and the high temperature water can beeffectively mixed with each other. Accordingly, hot water having a seteven temperature can be generated in the hot water storing tank 1. Asdescribed above, circulation operation is performed that the lowtemperature water is sucked by the circulation pump 13 and heated intothe high temperature water to be jetted between the hot water storingtank 1 and the electric heat type water heater 17, and that thetemperature layers are forcibly mixed and the temperature layerinterfaces are destroyed, and thus the water heated to the setapproximately even temperature can be speedily stored in the hot waterstoring tank 1.

Since the hot water storing tank 1 is filled with hot water having theapproximately even temperature from the top to the bottom as describedabove, it is unnecessary to use a hot water storing tank having acapacity twice as large as that of the hot water storing tank 1.Additionally, since the low temperature water and the high temperaturewater are forcibly mixed with each other, the speed of the temperaturerise of the water is high, hot water having a desired temperature can begenerated in a short time, and the cost of power consumption can besaved by shortening the heating time.

Comparing the water heater according to the embodiment with aconventional water heater shown in FIG. 4, the supply amount of hotwater of the water heater of the embodiment is 600 l, and that of theconventional water heater is 240 l, in the case where, for example, boththe capacities of the hot water storing tanks 1 and 51 are 300 l, boththe temperatures of supplied water are 45° C. That is, it is revealedthat the water heater of the embodiment has a capability to supply hotwater twice as fast as that of the conventional water heater.

FIG. 3 shows a Second Embodiment. Moreover, the same symbols areattached to components identical to the components of the FirstEmbodiment, and a description thereof will be omitted. In FIG. 3, thereference numeral 21 denotes a hot water generating and jetting deviceconnected to the hot water storing tank 1, 22 denotes a box-shapedcasing constituting the hot water generating and jetting device 21, and23 denotes a circulation pump provided in the casing 22. A suction pipe23A of the circulation pump 23 communicates with a suction port 24, anda jet pipe 23B of the circulation pump 23 communicates with a jet port25.

Here, the suction port 24 is formed in the body part 2A of the hot waterstoring tank 1 opposite to the water supply port 3, and the jet port 25is formed at the approximate center of the bottom plate 2B of the hotwater storing tank 1 so that a jetting direction of the jet port 25becomes orthogonal to a supplying water direction of the water supplyport 3. Additionally, the circulation pump 23 circulates the water inthe hot water storing tank 1 via the suction port 24 and the jet port25.

The temperature sensor 16 is provided in the suction pipe 23A, and theelectric heat type water heater 17 is provided in the middle of the jetpipe 23B of the circulation pump 23. Additionally, the control panel 18is provided in the casing 22, and connected to the electric heat typewater heater 17 and the temperature sensor 16 via signal wires (notshown).

In the thus constituted storage type water heater of the embodiment, thelow temperature water is made to impact and forcibly mix with the hightemperature water in the hot water storing tank 1 so that thetemperature layers are not formed, and thus the hot water having thedesired temperature can be speedily generated. In this point, the waterheater of the embodiment is basically the same as that of the FirstEmbodiment. However, according to the embodiment, since the hightemperature water generated by the hot water generating and jettingdevice 21 is jetted upward from the jet port 25 open-formed in thebottom plate 2B of the hot water storing tank 1 so that flow in a risingdirection is positively formed in the hot water storing tank 1, the hightemperature water flows upward and downward to be mixed with the lowtemperature water, and thus hot temperature water can be rapidlygenerated.

Moreover, although the electric heat type water heater 17, which has theelectric heater as a heat source, for generating the hot water isemployed in each embodiment, a gas combustion type water heater or anoil combustion type water heater may be employed as the heat source inthe present invention.

1. A storage type water heating method capable of downsizing a hot waterstoring tank, comprising the steps of: repeating sucking water,generating hot water by heating, jetting the hot water between a hotwater generating and jetting device, which is externally attached to thehot water storing tank having a water supply port and a hot water supplyport, and the hot water storing tank; destroying temperature layerinterfaces by forcibly mixing temperature layers generated by the hotwater in the hot water storing tank; and, generating high temperaturewater having an approximately even temperature in the hot water storingtank.
 2. A storage type water heating method for generating hot water tobe supplied outward from the water supply port provided at an upper sideof the hot water storing tank, comprising the steps of: heating water inthe hot water storing tank supplied from the water supply port by a heatsource while circulating the water by a circulation pump between asuction port and a jet port that are provided at a bottom side of thehot water storing tank; jetting the heated water from the jet port andforcibly mixing it with the water in the hot water storing tank so thathot water having an approximately even temperature is generated; and,further heating the generated hot water to a desired temperature by theheat source while circulating the generated hot water by the circulationpump.
 3. A storage type water heater comprising: a hot water storingtank having a water supply port at a bottom side of a tank body, and awater supply port at an upper side of the tank body; and, a hot watergenerating and jetting device connected to the hot water storing tank,wherein the hot water generating and jetting device has a circulationpump communicating with a suction port formed in the hot water storingtank so as to be positioned at the same height as or lower than thewater supply port, and with the jet port formed in the hot water storingtank separately from the suction port, heats water sucked from thesuction port by the heat source, generates hot water having anapproximately even temperature in a manner that the heated water isjetted from the jet port to be forcibly mixed with water in the hotwater storing tank, further circulates the generated hot water whiledetecting temperature of the generated hot water by a temperaturesensor, and heats the hot water to a desired temperature by the heatsource.
 4. The storage type water heater according to claim 3, whereinthe hot water generating and jetting device includes: a circulation pumpfor circulating water by sucking and jetting between the device and thehot water storing tank; a heat source for heating the water sucked bythe circulation pump; a temperature sensor for detecting temperature ofhot water sucked from the hot water storing tank; and, a control panelfor stopping operation of the heat source in accordance with a signaltransmitted from the temperature sensor, the signal indicating thesensor has detected the temperature of the water in the hot waterstoring tank has reached a desired temperature.
 5. The storage typewater heater according to claim 3, wherein the jet port is formed at abottom of the hot water storing tank.